Muffler



FIG. 1 is front, top, right-hand side perspective view of a muffler comprising a new, original and ornamental design;

FIG. 2 is a front view thereof;

FIG. 3 is a right-hand side view thereof;

FIG. 4 is a left-hand side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a rear view thereof.

The broken lines in FIGS. 1, 3, 5, and 6 are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a muffler, as shown and described. 